Rotary pump or motor



Dec. 27, 1938. H. A. CENTERVALL ROTARY PUMP on MOTOR Filed June 25, 1956 4 sheets-sheet 1 M v J2 v/0 v 65 i 30 J9 I 5 M 36 64 l 48 r o 43 52 I 1 4 34 23 O 4/ G M @3 l' O. 12a

' INVENTOR. H060 4. [ENTERVALL ammd H15 ATTORNEYS Dec. 27, 1938. H. A. CENTERVALL 2,141,171

ROTARY PUMP OR MOTOR Filed June 25, 1936 4 Sheets-Sheet 2 'H/S ATTORNEYS Dec. 27, 1938. I H. A. CENTERVALL 2,141,171

' ROTARY PUMP 0R MOTOR 4 Sheets-Sheet 3 Filed June 25, 19556 INVENTOR.

ill 60 A. CENTER/44M Dec. 27, 1938. H. A. CENTERVALL 2,141,171

ROTARY PUMP 0R MOTOR 4 Sheets-Sheet 4 Filed June 25, 1956 26/ INVENTOR.

BY #0 0 4 cz-wmamu KM; #WJ, 4W4

ms ATTORNEYS Patented Dec. 27, 1938 uNrrEo STATE ROTARY PUMP R MOTOR Hugo A. Centervall, Brooklyn, N. Y., assignmto Manly Corporation, ration of Delaware New York, N. Y., a corpo- Appllcatlon June 25, 1936, Serial No. 87,176

21 Claims. (Cl. 103-120) This invention relates to rotary fluid pumps or motors of the vane type whose capacity or output is variable independently of change of speed of rotation, that is to say, whose volumetric capacity per revolution can be regulated or varied. It relates more particularly to improvements in that portion of the pump bymeans of which .such variation or regulation of capacity is obtained.

Pumps and motors of this general class flnd their widest use at present as hydraulic devices, that is, devices for handling or whose motive fluid is a liquid, such, for example, as oil, and the pump or motor of the. present invention .will be described in connection with such use. It will be understood, however, that the inventionis applicable to pumps or motors operating with elastic fluids.

My copending application Serial No. 120,418, filed April 13, 1934,. motor, and while the construction therein disclosed has been found to be successful, the present invention concerns certain improvements, and the general object of the present invention is to simplify the construction, rendering the parts easier to assemble and reducing the cost of manufacture without compromising reliability of operation, and retaining the features of my previous pump of quietness freedom from vibration even when operating at hydraulic pressures up to 1,000 pounds per square inch, or more, and at all loads from zero to the maximum output for which the pump or motor isdesigned.

Pumps and motors of the type under consideration comprise a rotor carrying vanes which are movable in and out in a general radial direction, and arranged to rotate within a chamber having side walls which closely flt the-sides of the rotor and side edges of the vanes. A trackway for guiding and controlling the inward and outward movement of the vanes as the rotor revolves comprises'one or more pairs of abutvments and interconnecting flexible track elements. The work of the pump or motor is done while the vanes travel across the arcuate length of one of these abutments of each pair, termed the radially from thesurface of the rotor, the working fluid being received on one side of this arc or abutment and discharged on the other. The other abutment of each pair serves to separate one of these discharge areas from the adjacent inlet area. The regulation of the capacity of the pump or motor is effected by moving or adjusting the working or pumping abutmentradially relates to such a pump or of operation and substantial working or pumping arc, which is spaced with respect to the circumferential surface of the rotor, the flexible track elements having extensible connections with one abutment thereby permitting such adjustment without changing the radial position of the other abutment of each pair, which is preferably arranged in fixed position adjacent the-surface of the rotor. portant object of the invention is to improve the construction and arrangement of this vane track and its associated mechanism by means of which the volumetric capacity per revolution of the rotor of the pump or motor'is determined, and regulated or varied, and by which the inward and outward movements of the vanes are controlled.

In the present pump construction the allning means (that is, the means for maintaining even relationship between the overlapping parts of the track surface at the extensible connections),

' and the flexing control means (that is, the means for'fiexing the flexible portions of the track) are arranged on the abutments, whereas in the earlier construction both of these means were on the end plates which form the side walls of the pump chamber.

In the former construction also the connecting or flexible track elements were secured to the movable abutments, whereas in the present construction the flexible track elements are preferably secured to the flxed or stationary abutments, the flexing and aligning means being carried by the movable abutments. In addition, in my present construction, the stationary abutments and flexible track elements comprise a unitary composite structure which is mounted on a continuous ring-like spacer block to securely hold Anim-' the flexible track elements in place with their surfaces in proper relation fixed abutment.

The arrangement of the present invention furthermore provides certain improvements in the particular mechanism employed for aligning and controlling the flexing of the flexible track elements. The present invention still further provides for a pump. in which the direction of flow of fluid may be reversed, or a motor whose direction of rotation may be reversed, and the pump capacity per revolution, or the power output, may be continuously varied, that is, varied in infinitely small amounts in both directions of fluid flow or motor rotation, as the case may be. a

The invention will be understood from a consideration of the accompanying drawings which illustrate, by way of example, a number oi embodiments of the invention in a pump of variable capacity.

to the surface of the taken along the line 2-2 of Fig. 1;

Fig. 3 is a view in side elevation showing the pump casing with its adjacent end plate in position, the rotor and easing cover being removed.

Fig. 4 is a perspective view of a pair of 'flexible track elements with part of the flexing control mechanism integral therewith;

Fig. 5 is a perspective view of a movable abut-- ment and'its associated parts;

Figs. 6 and 611 show the relative positions of the movable abutments and flexible track elements andassociated mechanism in their two extreme positions of adjustment;

Fig. 7 is'a view transverse the axis of rotation of a modified form of pump with the enclosing casing, driving shaft and end plates removed, the left half being partly in section;

Figs. 8 and 8a are fragmentary views somewhat similar to Fig. 7 showing for this modification the relative positions of the movable abutments and flexible track elements and their associated mechanism in their two extreme positions of adjustment; and

. Figs. 9 and 10 are views, partly schematic= showing another modified form of pump with the enclosing casing, driving shaft and end plates removed, in which the direction of flow of the fluid may be reversed, 3

Referring first to the embodiment of the invention illustrated in Figs. l-6a of these drawings, as shown in Fig. 2 the pump includes a caslng l0 and a cover H which are provided with suitable cooperating faces and which are held together by screws i2, appropriate packing I3 being used to prevent leakage. The pump is supported by a base l5 formed integrally with the casing l6.

A pair of disc-shaped end plates 26 are positioned within the interior of the casing i6, each of which is formed with a hub 2| which snugly fits into a suitable bore in the casing in and cover II respectively. Theend plates 20 are separated by a pair of spacer blocks or central distancepieces 23 (Figs. 1 and 2) which form substantially fluid tight fits therewith.

Each spacer block has a nearly semi-circular outer surface adapted to substantially conform with the interior of the casing Ill and an inner surface suitably cut away to provide space for other parts of the pump to be later described. The spacer blocks 23 are diametrically positioned and their parallel'opposing ends in this embodiment are horizontal when the parts are in position. 'Each spacer block is located by a bolt 24 (to be referred to later) whose end extends be yond the exterior of the casing I 0 and is threaded to receive a nut 25 (Fig. 2) and each spacer block is also provided with holes through which pass the screws l2 as clearly shown in Fig. 1.

The pump rotor .26 is positioned in the chamber formed between 'the end plates 20 and the two spacer blocks 23 and is of a width slightly less than that of the spacer blocks 23. Rotor 26 is rotatably supported upon its hubs 21 which extend into the bores of the hubs 2| of the end plates 20. The arrangement is such that the rotor 26 is free to rotate while forming substantially fluid tight running fits with the cooperating zontal ends of the spacer blocks 23.

surfaces oi the end plates 20. Rotor 26 is also formed with a plurality of substantially radial vane slots 28, each of which is provided with'a vane 29 of substantially the same width as the rotor 26 and preferably of a length slightly-less j than that of thevane slots 23.

' The rotor is driven in such a way that slight misalignment of the rotor and drive shaft, or end thrust of the shaft, will. not cause the rotor to bind. The driving shaft 3| is rotatably support:- ed by a bearing element 32 carried by the cover II and by another bearing element 33 carried in a bore formed in the casing l0 through which .the shaft 3| passes, said bore being closed'by a cover plate 6.

The driving shaft 3| passes loosely and slidably through the bore of the rotor 26 and is suitably keyed thereto, as by a key 34 slidably engaging a keyway in the bore'of therotor 26, in such manner that the driving. shaft 3| may move lengthwise with respect to the rotor.

this embodiment the space surrounding the rotor 26 is divided by a pair-of fixed abutments 36 (Fig. l) which extend inward from the spacer blocks23 and are positioned above and below the rotor 26. Each fixed abutment 36 is substantially the same width as the spacer blocks 23 and is provided with an interior arcuate surface adapted to form a substantially fluid tight sliding fit with the endsof vanes 29. Accordingto this embodiment of the invention these abutments are formed on the heads of. bolts 24. The inner arcuate surfaces of the fixed abutments 36 form part of the vane track for guiding the vanes and along which the exposed ends of the vanes 29 move in sliding contact as the rotor revolves. These surfaces are preferably concentric with the periphery ofthe rotor 26 and of-an angular length equal to or slightly greater than the angular distance between a pair .of adjacent vanes 29.

The working or pumping chambers of the two pumping sections are formed by means of two diametrically positioned members 40, hereafter termed movable abutments,-one of which is shown in perspective in Fig. 5. The pumping chambers are'comprised by the spaces between the two adjacent vanes'which, at any given instant, are moving in contact with a portion of the inner ends of each of these movable abutments 40. The size of these pumping chambers and hence the volume of fluid delivered by the pump per revolution of the rotor are determined by the distance of the inner ends of abutments from the surface of rotor 26. vary theoutput or capacity, that is, the stroke of the pump, these members are arranged to be radially adjustable, preferably conjointly.

' Since full operating fluid pressure'exists on opposite sides in. the direction of the circum- In order to regulate or ference of the rotor) of movable abutments 40," I

they are formed with rectangular portions 4| having a width equal to the distance between the opposing faces of the end plates 20 and a height equal to the distance between the opposing hori- Each abutment 40 is slidably supported thus by its rec.- tangular portion 4| and the arrangement is such that portion |l forms substantially fluid'tight sliding joints with the opposing faces of the end plates and the supporting horizontal ends of the spacer blocks 23. A cylindrical portion 42 extends outward from the rectangular portion 4| of each movable abutment 40 and projects throughan opening l8 in the pump casing l0 and 42. For connection to such output or sroke" adjusting mechanism the links '42 are provided. The maximum inward and outward movement of I abutments 4D is limited by suitable stops. In this instance these include the enlarged inner ends of the abutments and washers 43 which are adapted to be held in appropriate grooves in the cylindrical portions 42 as indicated by dotted lines at 44 in Fig. 1. These washers are U- shaped that is, open at one side to ,permit assembly. i

The portion '45 of the inner end of each movable abutment which constitutes the outer wall of one of the pumping chambers, forms .part of the vane track which will be referred to as the "pumping arc.

center line of a rectangular portion 4|, and the two pumping chambers or pumping arcs are diametrically opposite one another.

Fluid is admitted to the pumping chambers at one side of the vanes as they approach each pumping chamber, and fluid is discharged from the pumping chambers in like manner as the vanes recede from each pumping chamber. The inlet and outlet ports by which this is accomplished are located in the right hand end plate 20 as viewed in Fig. 2, although the plane on which the section of Fig. 2 is taken does not pass through any of these ports. These ports are shown, however, in Fig. 3 as narrow arcuate slots, and will be described in more detail further on, together with their connections with the main inlet and outlet passages of the pump.

The pumping arcs are preferably of length, in a circumferential direction, equal to or slightly greater than the distance between the ends of a pair of adjacent vanes29 when in their maximum radially outward position. The arcs'45 may be of any preferred curvature but are preferably made concentric with the rotor 26 when the movable abutments 40 are in the position at which the pump is intended to receive its'greatest use.

,In this embodiment the pumping arcs 45 are concentric with the rotor 28 when the movable abutments 4!! are midway between their extreme inward and outward pos tions of adjus ment. By this arrangement the radial movement of the vanes 29 while passing across the pumping arcs 45 and subject to unbalanced working pressure is kept at a minimum and is so small that in practice it is negligible at all outputs.

The vanes '29 are conveyed or guided in their in and out movement to and from the fixed abutment 's 35 and movable abutments 40, as the rotor revolves, by means of connecting track elements which for convenience are termed flex ble track elements, although it will be understood that parts thereof may be rigid, as shown for example in Figs. 1 and 4. Up to this point the pump of my present invention is not unlike the one disclosed in my earlierap'plication referred to above. Ac-

The center line of each pumpingarc is preferably in line with the horizontal cording to the embodiment of the invention shown in Figs. 1-6a, one of the ends of each of the flexible track elements is adapted to be fixedly supported upon the fixed abutments 35, and the flexible elements are formed in pairs. As shown in Figs. 1 and 4, each pair of flexible track elements, includes a central portion which is preferably rigid and of substantially the same width as the fixed abutment 36 with which it cooperates. The central portion 50 is adapted to fit within an appropriate recess in the spacer block 23 and is provided with a suitable hole, not shown, through which the bolt 24 passes (see Figs. 1 and 2). The arrangement is such that the central portion 50, the corresponding spacer block 23 and fixed abutment 36 are firmly held together so that the coniguous inner surfacesof the flexible track elements are held continuously in smooth alignment with the arcuate inner surfaces of the fixed abutment 35.

The inner ends of the movable abutments 40 have forked arms 46 extending in an approximately circumferential direction from the rectangular portions 41 (Figs. 1 and 5). These. arms, as will be seen presently, coact withv and control the position and flexing of the connecting or flexible track elements. The inner arcuae edges of arms 46 are provided with arcs 41 adjacent each side of pumping arc 45 which form part of the vane track. The arcs 41, which may have any suitableradius of curvature, smoothly join the pumping arcs 45 and extend a short distance therefrom.

A flexible arm 52 (Figs. 1- and 4 projects from each end of the central portion 50 of the fiexible track elements and extends in an approximately circumferential direction toward its corresponding movable abutment 40 with which it is adapted to connect and cooperate in all positions ofadjustment bf the movable abutment 40. Each arm 52 terminates in a relatively rigid end portion 53 which is adapted to slidably fit within the fork of the adjacent forked arm 46, and the flexible arms 52, which may be of any suitable width, are here shown as of the same width as these rigid end portions 53. The inner surfaces of the rigid end portions 53 are formed with arcs 54 (Figs/1 and 4) which constitute parts of the vane track and which preferably have the same curvature as that of the arcs 41 on the forked arms 46 with which they are adapted to overlap and connect at all times.

Each vane 29, during each revolution of the rotor 26, passes to and from each of the elements of the vane track and as these vane track elements are eight in number (two movable abutments 40, two fixed abutments 36 andfour flexible track-elements) each vane therefore passes from one track element to' another'eight times per revolution of the rotor 26. Transfer of a vane 29 from one vane track element to another therefore occurs in a'very short interval and frequently at comparatively high speeds of relative movement between the end of the vane 29' and the vane track surfaces. This frequency and speed of transfer make it necessary to continuously maintain each vane track element in smooth alignment with its adjacent elements at all strokes" of the pump, as any roughness or uneveneness of the surface of the vane track would interfere with proper movement of the vanes, resulting in unsatisfactory operation of the pump. There is no relative movement between the stationary abutments' 35 and the adjacent portions of the flexible track elements,

and alignment between their contiguous vane track surfaces at their juncture is readily maintained by the arrangement already described. Radial adjustment of the movable abutments 45 produces relative movement, however, between the inner ends of these abutments and the flexible track elements so it is necessary to provide means, to be described presently, which assure and maintain proper alignment between the contiguous portions of their vane track surfaces.

Each vane 29 is also reciprocated twice for each revolution of the rotor 26 (which in practice will frequently rotate at speeds of 800-1200 R. P. M.) so that the vanes 29 attain relatively high speeds or radial movement and are subject to rapidly recurring reversal in the direction of their radial motion. It is therefore also necessary to regulate and control the rates of inward and outward movement of the vanes 29, that is, their radial acceleration and deceleration, in order to obtain satisfactory operation of the pump and it is very important and practically essential that their radial movement be smooth and without sudden or violent increase or decrease of radial velocity. It is also important and practically essential that the outward radial acceleration of the vanes be such that the force necessary therefor is within the limit of the centrifugal force produced by rotation of the rotor and acting to urge the vanes outward, in order to maintain continuous contact between the ends of the vanes and the vane track surface.

Radial'movement of the vanes 29 is controlled by the vane track, and their rates of radial movement are accordingly regulated by controlling the shape of the vane track througout the range of adjustment of the movable abutments 30. This control is accomplished by proper proportion of the several elements comprising the vane track and by exerting upon the flexible portions of the vane track simultaneously with the adjustment of the movable abutments Mi, force or forces which alter their curvature to a predetermined extent and in a predetermined manner, so that their shape is positively controlled throughout the entire range of adjustment of the movable abutments 50. In the embodiment of Figs. 16a the mechanism for exerting this force upon the flexible portions of the vane track includes that employed for maintaining alignment between the contiguous portions of the vane track surfaces of the movable abutments 4d and flexible track elemerits, and this mechanism which is utilized to perform both of these functions will now be described.

The rigid end portions 53 of the flexible track elements are provided with slots (Figs. 1 and 4), for convenience termed the guide slots, which are preferably concentric with the arcs 54. Keys 45 fit within these guide slots. These keys 48 (Fig. i) may be of any suitable shape and are shown as cylindrical pins fixedly supported upon the forked arms 4'5 of the movable abutments 40, as by closely fitted holes 49 (Fig. 5). The guide slots 51 and their keys 48 cooperate to radially position the rigid end portions 53 with respect to the forked arms 45, and the arrangement is such that the corresponding surface of each arc 5% is maintained even with the surface of its respective adjacent are 41 on the edges of the forked arms.

While the rigid end portions 53 and the arms 46 are thus radially positioned with respect to each other, the guide slots 51 and their keys 48 if employed alone are not capable of maintaining the necessary alignment between the arcs l1 and 54 nor of exerting the desired bending force upon the flexible arms 52, as the rigid "end portions 53 would then be free to swing around the keys 48 so that there would be no assured alignment and no positive control of the curvature of the flexible arms 52.

The rigid end portions 53 of the flexible track elements are accordingly provided with control members 55 having one of their ends formed integrally with or securely attached to the rigid end portions. The control members 55 are formed with slots 58 (Figs. 1 and 4) for convenience termed the control slots, which may be I given any suitable shape, depending upon the c1; 'vature which it is desired to obtain in the flexible arms 52. As here shown the control slots 58 have the same curvature as the arcs 5d and are concentric therewith, and these control slots 58 are also provided with keys 59 which are carried by the forked arms 65 of movable abutments 40.

These control slots 53 and their keys 55 cooperate with the guide slots 5'! and their keys 48 to maintain the arcs 5Q concentric with the arcs H and to keep the oven-lapping portions of these arcs coincident, while at the same time exerting bending force upon the flexible arms 52 as will be more fully explained presently.

Substantially all radial movement of the vanes 29 occurs while they are moving along that portion of the vane track constituted by the flexible arms 52, so that the rates of their radial movement is controlled by the shape of these flexible arms. The inner surfaces of the flexible arms 52 may be given any suitable curvature or shape but are preferably so formed that they smoothly join with the arcs 5d and with the arcs on the vane track surfaces of the fixed abutments 36. The inner surfaces of the flexible arms 52 are also preferably ground to have the configuration producing the desired rates of radial acceleration and deceleration of the vanes is when no flexing or re-forming force is exerted upon said flexible arms 52 by the mechanism provided for this purpose. In this embodiment the arrangement is such that the flexible arms 52 are free from this force when the movable abutments W are midway between their extreme inward and outward positions of adjustment, as shown in Fig. 1, and the inner surfacesof said arms 52 are ground to closely approximate segments of a parabola when the movable abutments Ml are in this midposition which corresponds to approximately half stroke" of the pump. The flexible arms 52 may also be of any suitable thickness and in the embodiment of Figs. 1-6a are of variable thickness, being thinnest at their central portions and increasing in thickness towards their ends.

Adjustment of the movable abutments 4d radially outward from their mid-position shown in Fig. 1 increases the length of the stroke of the vanes 29 and the output or capacity of the pump and produces relative movement between the forked arms at and the rigid end portions 53 of the flexible or connecting track elements. The keys .8 and as at the same time move outward in a straight path and tend to impart like motion to the rigid end portions 53 and controLmem- .prevented.

Relative movement in an approximately circumferential direction is thus produced between lap between portions of the arcs 41 and 54.

the arms 45, which carry the keys 48 and 59. and the rigid end portions 58-, and hence between the arcs 41 and 54, increasing the circumferential length of the vane track and shortening the over- All relative movement between these parts is confined to a path determined by the shape of the guide slots 51 and control slots 58 and as these are preferably concentric with the arcs 54, which midposition,

preferably have the same curvature as the arcs 41, the surfaces of the arcs 41 and 54 are at all times maintained concentric and their overlapping portions coincident.

The constraining action which produces this controlled relative circumferential movement also exerts bending If the guide slots 51 and their keys 48 were alone employed the rigid end portions 53 and their attached control members 55 would tend to rock to a certain extent, around the keys 48 as centers, toward the rotor 28 which would tend to straighten the flexible arins 52 and decrease their curvature. The-control slots 58 andtheir keys 59 positively control this rocking and the shape of said slots determines the amount of rocking which occurs. In this instance control slots 58 is such that, as the-movable abutments 40 are moved radially outward from their the control members 55 are rocked toward the rotor to a greater extent than would result if the guide slots 51 and their keys 48 were alone provided and the control members 55 otherwise unconstrained.

This increased rocking of the control members 55 and rigid end portions 53 exerts increased positive bending force upon the flexible arms 52 which tends to straighten them and decreases their curvature, with the result that the parabolic portions of the vanetrack are flattened as the movable abutments 40 are moved outward from their mid-position. This is best shown in" Fig. 6a which shows the relative positions of the vane track elements when a movable abutment. 48 has been radially adjusted to its extreme outward position, the dotted circular line indicating the periphery of the rotor 26.

The action of the parts just explained is reversed when the movable abutments 40 are adjusted radially inward from their mid-position shown in Fig. 1. The stroke of the vanes 25 and the capacity or output of the pump are then reduced. Relative circumferential movement between the forked arms 45 and rigid end portions 53 takes place in the opposite direction, the circumferential length of the vane track is shortened and the overlap between portions of the arcs 41 and 54 is increased, the surfaces of said arcs 54 being maintained concentric with the surfaces .of the arcs 41 and their overlapping portions coincident.

The control slots 58 and their keys 58 again function to positively control the rocking oi the control members 55 and rigid end portions 53 around the keys 48 as centers and the shape of the control slots 58 determines the amount of rocking which occurs. In this instance the con trol members 55 and rigid end portions 53 tend to rock outward or away from the rotor 25, which tends to increase the curvature ofthe flexible arms 52, but the shape of the control slots 58 is such that the control members 55 are rocked to a greater extent than would occur if guide slots 51 and their keys 48 alone were provided and the control members 55 otherwise unconstrained.

force upon the flexible arms 52..

the shape 0! they Increased positive bending force is thereby exerted upon the flexible arms 52.

This increased bending force still further increases the curvature of the flexible arms 52 and the arrangement is such that they progressively approach and assume the approximate curvature of arcs concentric with the rotor 25 as the movable abutments 40 continue to be moved radially inward from their midposition. This is best seen in Fig. 6, which shows the relative positions of these parts when its exteme inward position of adjustment.

The guide slots 51 and control slots 58 and their keys 48 and 59 perform still another function and serve as dampers for any vibrations that the flexible arms 52.

Whenever the movable abutments 40 are moved toward their mid-position shown in Fig. l, the flexible arms 52 progressively return toward their normal curvature'which is resumed when the movable abutments 40 reach this mid-position. Through the entire range of adjustment, therefore, the curvature of the flexible arms 52 is increased and the circumferential length of the vane track simultaneously shortened whenever the movable abutments 40 are moved radially inward; and the curvature of the flexible arms 52 is decreased and the circumferential'length of the vane track is ever the movable abutments 48 are adjusted radially outward. The curvature of the flexible arms 52 isthus definitely controlled throughout the entire range of adjustment of the movable abutments til.

The flexible arms 52 may be made to assume almost any desired curvatures as abutments 40 are adjusted radially, so that radial movement of the vanes 29 may be made to occur at practically any predetermined rate. The construction herein described, however, produces radial movement of the vanes 29 at rates which in practice have been found to be entirely satisfactory. The radial acceleration and deceleration of the vanes, as they move across the approximately parabolic curves of the flexible arms 52, are free from sudden or violent change and in fact are substantially constant and the outward acceleration is well below that which can be produced by the centrifugal force which acts upon the vanes so that their ends are continuously maintained in contact with'the vane track surface. I

In practice it has been found that satisfactory operation of the pump and movement of the vanes is obtained with a vane track closely-approximating that herein described and which consists of arcs having only four different radii of curvature. These arms are as follows, reference being made to Figs. land 4-611, by way of illustration:

(1') The pumping arcs 45 on movable abutments 45. I (2) The arcs on the vane track surfaces of the fixed abutments 35.

3) Arcs (51,54) extending circumferentially from each end oi? each of the pumping arcs 45 and having a common tangent therewith at their juncture. These arcs extend oh to the flexible arms 52.

(4) Arcs (not designated by a reference numeral) extending circumferentialiy from the ends of each of the arcs on the vane track surfaces of the fixed abutments 55, having common tangents therewith at their juncture, and extending along the flexible arms 52, connecting a movable abutment 40 is in' the movable immediately adjacent both the fixed abutments 36 and movable abutments 40 when the movable with and also having common tangents with the arcs' (.41, 54) at their juncture; It will be ob-" served that all of these arcs have common tangents with their contiguous arcs at their juncture. According to this arrangement, a pair of arcs, comprising-one each of the arcs '(41, 54)

and of thearcs extending along the flexible arms 52, connect the pumping arcs 45 with the arcs onthe vane track surface of the fixed abutments 36, so that the inner surfaces of track elements 52, 55 and 46 may be formed by arcs of only these two curvatures. This arrangement is convenient in grinding the surfaces of the vane track and assures tangential relationship of each section or arcof the vane track with its contiguous sections or arcs in all positions of adjustment of the movable abutments 49.

In a pump embodying the type of construction described herein there is substantially no change in the curvature of the portions of the vane track ple, the arcs 41 may have the same curvature as the pumping arcs 45, or the guide slots 51 and control slots 58 may be given a curvature different from that of the arcs 54 and may even be straight (which may be desirable in manufacture) as any errors theoretically resulting therefrom will be very slight and in practice may frequently be neglected. Also each pair of guide and control slots 51 and 58. may be combined to form a single slot of increased length; or they may be positioned upon the forked arms 46 of the movable abutments 40'instead of upon the rigid end portions 53 and control members 55,

the keys 48 and 59 then being carried by the rigid end portions 53 and control members 55.

The construction and arrangement'of the vane track elements and associated mechanism areimportant features of this invention and havenumerous other advantages. For example, throughout the entire range of adjustment of pumping capacity they provide smooth alignment of the vane track elements and tangential relationship of the flexible arms with those adjoining sections of the vane track which have fixed curvatures. They make the parts substantially self -aligning as the guiding and controlling mechanisms are carried by the parts themselves; this simplifies manufacture and reduces the possibility of improper fit as it is only necessary to accurately position the keys 59 with respect to their corresponding arcs 41 and to accurately position the slots 51 and 58 with respect to the arcs 54. A different material may be used, if desired, for each of the different elements of the vane track (that is, the fixed abutments, movable abutments and flexible track elements) or they may be treated to provide different properties in each. The parts are all relatively simple and in- 4 expensive to manufacture and may readily be made interchangeable.

The vane tracls elements are also easy to asinlet or suction channel semble. The flexible track elements and fixed abutments 36 are assembled with their spacer blocks 23 and fastened in place by the nuts 25. The movable abutments 40 are then inserted and are radially adjusted and properly aligned with respect to the-flexible track elements, the keys 48 and 59 then beinginserted in the holes 49 and through the guide slots 51 and'control slots 59 respectively. The keys require no fastening as they are held in place by the end plates 20.

The fluid circuit of the pump includes a fluid 60 and a fluid outlet or discharge channel6l (Figs. 2 and 3) .connecting respectively with inlet and outlet openings 62 and 63.

formed in the adjacent end plate 20 shown at the right in Fig. 2. Discharge channel 6| is connected with discharge ports 65. Thisend plate 20 is, also provided with two pairs of vane slot ports 66 and 61, respectively positioned to register with the inner ends of the vane slots 28 and connected by passages 68 and 69 with the ports 64 and 65. respectively. The arrangement is such that the inner ends of the vane slots 28 are connected with fluid under the same pressure as the fluid acting upon the outer ends of their corresponding vanes 29 while said vanes are passing from one abutment to another and hence the vanes 29 are substantially in hydraulic balance when they are moving radially and while passing along the flexible arms '52. The vane slot ports 61 are preferably made of such length that they also connect with the inner ends of those vane slots 28 whose varies 29 are in contact with the vane track surfaces of the fixed abutments 36 and the pumping arcs 45, so that fluid from the outlet ports 65 is supplied to the inner ends of such vanes to assist in holding their ends firmly in contact with the vane track surfaces as they move across the fixed and movable abutments.

Suction channel 60 is appropriately connected with its pair of arcuate inlet ports 64 It will be understood that the arrangement of inlet and outlet ports and spaces and of the pumping arcs and fixed abutments 36 produces hydraulic balance of-the rotor in a radial direction. The rotor and vanes may also be balanced hydraulically in an axial direction by providing suitable balance ports in the left hand end plate 20 which is adjacent the cover H, each of these balance ports being adapted to contain fluid under the same pressure as that in its axially opposite port or vane .slot port in the other end plate 20.

When the rotor 26 revolves in a clockwise direction as viewed in Fig. 1, fluid enters through the inlet port's64 and passes into the inlet space of each of the two pumping sections of the pump, that is, into the space between the peripheral surface of the rotor and the surface of the vane track on the following or rear side of each movable abutment 40. Pumping is accomplished by the vanes 29 as they move across the pumping arcs 45 and thus force fluid into the .outlet spaces of each of the twoworking sections of the pump, from which it passes out through the outlet ports 65 and into the outlet channel-6|. The outlet spaces correspond with the inlet spaces but are on the leading or front sides .ofthe movable abutments. As already stated, the size' of the pumping-chambers and the volume of fluid delivered by the pump are determined by the distance of the pumping arcs 45,.from the rotor 26; as this distance may be continuously varied in infinitely small increments from minimum to maximum, the size of the pumping chambers and the volume of fluid delivered by. the pump may be plates '28 casing l8 and may be located circumferentially as not shown. It isheld against by a dowel pin,

which pass through the rotation by the bolts I2 holes H2.

The unitary spacer port for all of the vane track elements. abutments I36 are wedge-shaped and accordingly are supported by their outer portions which are received within appropriately shaped recesses formed in the spacer block I23. The movable abutments I48 are slidably supported upon the spacer block I23 by parallel slideways formed therein, in substantially the same manner as in the embodiment first described, and their cylindrical portions I42 extend outward from the rectangular portions HI and project through suitable holes in the spacer block I23. In this instance the flexible track elements which connect the fixed abutments I36 and movable abutments I48 are formed integrally with the fixed abutments I36 or securely attached thereto.

All of the vane track elements and associated mechanism are thus carried by and positioned upon the same single member proper alignment and flt of these parts are thus readily obtained and the possibility of errors is reduced. These elements. when in position upon the unitary. spacer block I23, cooperate to form a complete vane track which'in effect is a unit independent of any other part of the pump exblock I23 forms the sup- .cept the adjusting mechanism, so that proper function and positioning of one element with respect to the others is assured. The end plates 28 are also axially positioned with respect to each other by the unitary spacer block I23 and, as the end plates support the unitary spacer block I23 therefore forms a common reference or positioning member for substantially all of the working parts of the P The vane track elements are all generally similar to those of the embodiment first described. The guide slots .I48 are, however, shown as formed in the forked arms I46 of the movable abutments I48 and are preferably concentric with the arcs I41 thereon (which correspond to the arcs 41 of the embodiment first described) although they may have a different curvature or may even be straight as in the flrst'described embodiment. The rigid end portions I53 of the flexible track elements are provided with suitable retaining means, shown as bushings I51 (which may be welded in place if desired), for appropriate. keys or pins I59 whose ends are slidably fitted in the guide slots I48. The arrangement and proportions are such that the keys I58 may move lengthwise of the guide slots I48 but prevent any other relative movement between the rigid end portions 153 and arms I46. The rigid end portions I53 are thus radially positioned with respect to the arms I46 and corresponding portions of the arcs I54 on the inner surfaces of said The fixed and position the rotor,

rigid end portions are maintained substantially even with the surfaces of the arcs I41.

The rigid control members I55 are shown as continuations of the rigid end portions I53 and their ends I56 are adapted to slidably fit in ap-' propriate control slots I58 here shown as formed in the unitary spacer block I23. The arrangement is such that the control members I55 may also pivot a slight amount around their ends I56 as centers, as may be required at various positions of adjustment of the movable abutments I48.

The vane track elements of this modified form.

cooperate and function in much the same way as those of the embodiment .flrst described. Radial adjustment of the movable abutments I48 produces relative circumferential movement between the forked arms I46 and the rigid end portions I53 of the flexible track elements and thus alters the circumferential length of the vane track. This movement of the rigid end portions I53 causes the control members I55 to tend to rock around the keys I59 as centers, and the amount of this rocking is controlled by the control slots I58 which are shaped and positioned to produce rocking of th'e control members I55 to the extent necessary to maintain the arcs I54 concentric with the arcs I41 in all positions of the movable abutments I48.

As in the embodiment first described, this controlled rocking of the control members I55 also exerts positive increased bending force upon the flexible arms I52 to positively control their curvature throughout the range of radial adjustment of the movable abutments I48. The arrangement, preferably, is such that no bending force is exerted upon the flexible arms I52 when 'the movableabutments I48 are in their midwhen they are adjusted radially inward from this mid-position the control members I55 exert increased positive bending force upon the flexible arms I52 which increases their curvature. Figs.

8 and 8a show the relative positions of theseparts when a movable abutment I48 is radially adjusted to its extreme-inward and extreme outward positions respectively, the dotted circle indicating the periphery of the rotor.

The flexible arms I52 progressively approach their normal curvature whenever the movable abutments I48 are moved toward their mid-position so that throughout the entire range of adjustment the curvature of the flexible arms I 52 is decreased whenever the movable abutments I48 are moved outward and the circumferential length of the vane track thus increased, and the curvature of the flexible arms I52 is increased whenever the movable abutments I48 are adjusted radially inward and .the circumferential length of the vane track thus shortened.

Among the advantages of this modified formis that the movable abutments I48 are still further simplified and the size of their inner ends is materially reduced. The flexible track elements and control members I55 may be conceniently made from relatively thin strips of material bent to approximate shape and suitably fastened to the wedge-shaped flxed abutments I36 and to the bushings I51, so that it will be necessary to remove only a comparatively small amount of material in making these parts. As

in the embodiment first described, the vane track elements are substantially self-aligning.

Figs. 9 and 10 show the rotor and vane assembly, spacer block and vane track elements of a further modification of the invention in which the direction of flow of the fluid may be reversed and the capacity of the pump continuously varied in infinitely small amounts in both directions of The vane track elements of this modification are substantially identical with those of the embodiments shown in Figs. 16a'from which they differ principally in that all four abutments are radially adjustable. A pair of adjustable abutments 236 are accordingly substituted for the fixed abutments 36 of the first described embodiment and are slidably supported upon a unitary spacer block 223. The flexible track elements are shown as made integrally with the abutments 235 or as having one of their ends suitably attached thereto, their opposite having sliding connections with abutments 250.

The inner end of each of the abutments 236 and 260 is formed with an are 2 85, similarto the pumping arcs $5 of the embodiment first described, which is smoothly joined by the contiguous portions of the vane track surface. The outer ends of the cylindrical portions 262 of these abutments may be conveniently connected with appropriate adjusting mechanism, not shown, by which they may be radially adjusted, and the arrangement is preferably such that the two abutments 236 are conjointly adjusted and that the two abutments 2 50 are likewise conjointly adjusted. I

The pump functions in the same manner as the embodiment first described when the radial distance from the rotor to the track surfaces of the abutments 236 is less than the radial distance from the rotor to the track surfaces of the abutments 260. The abutments 236 then per form substantially the same functions as the fixed abutments of the first and second described embodiments and divide the space surrounding the rotor into two pumping sections, each comprising a working or pumping chamber flanked by inlet and outlet spaces. The abutments 2d function in the same manner as the movable abutments w of the embodiment first described and the arcs 245 on the inner ends thereof are then the pumping arcs. With the rotor revolving in a clockwise direction as viewed in Fig. 9, the spaces 28 will then be the inlet or suction spaces and the spaces 26! will be the outlet or high pressure spaces. The volumn of fluid delivered by the pump in this direction of fluid flow may be continuously varied from zero. when the abutments 236 and 2&0 are equidistant from the rotor, to maximum, when the abutments 236 are in their extreme inward and the abutments Mil in their extreme outward positions of adjustment respectively, as shown in Fig. 9.

The functions of the abutments and the direction of fluid flow are reversed when the abutments are adjusted so that the radial distance from the rotor to the track surfaces of the abutments 2&0 is less than the radial distance from the rotor to the track surfaces of the abutments 236. The abutments 240 then perform the functions of the fixed abutments, dividing the space surrounding the rotor into two pumping sections, and the abutments 236 function as the movable abutments, the arcs 245 on the inner ends thereof then being the pumping arcs. With the rotor continuing in the clockwise direction,

as viewedin Fig. 10, the spaces 2 will then be the inlet or suction spaces and the spaces 26 will then be the outlet or high pressure spaces. The volume of fluid delivered in this direction of fluid flow may likewise be continuously varied from zero to maximum, the maximum volume being delivered when the abutments 236 are in their extreme outward and the abutments 260 in their extreme inward positions of adjustment respectively, as shown in Fig. 10.

The volume of fluid delivered by the pump in bothdirections of fluid flow may, therefore, be continuously varied throughout the entire range from'zero to a maximum which is equal to the maximum volume that would be delivered by a comparable non-reversible pump. The abutments 236 and 240 may be adjusted with respect to each other in numerous relative arrangements as no fluid will be delivered by the pump when all abutments are equi-distant from the rotor, while fluid will be pumped in one direction or the other whenever there is any difference in the radial distances from the rotor to the track surfaces of the abutments 236 and 240 respectively.

Instead of simultaneously adjusting both pairs of abutments 236 and 240, variation of capacity may be obtained by adjusting either pair, leaving the other pair in close proximity to the surface of the rotor, as in the case of the fixed abutments 0f the embodiments of the invention shown in Figs. 1-6a and 7-8a. With this method of operation, at zero stroke, that is, when the output of the pump is zero, all four abutments are equidistant from but close to the surface of the rotor. When it is desired to cause the pump to deliver fluid, that pair of abutments is adjusted outwardly from the rotor which will produce the desired direction of fluid flow, and the extent of such outward movement determines the fluid output of the pump.

Alignment of .the contiguous vane track surfaces of the abutments 2M) and of the flexible track elements is at all times maintained and curvature of the flexible arms 252 is decreased whenever the circumferential length of the vane track is increased and their curvature is increased whenever the circumferential length of the vane track is shortened.

Reversal of direction of fluid flow may also be obtained when fixed abutments are employed, as in the first and second described embodiments, by

increasing the radial distance between the rotor from the track surfaces of the fixed abutments and by providing movable abutments capable of being so adjusted radially that their track surfaces may be positioned a distance from the rotor which is less than, equal to or greater than the radial distance separating the rotor and the track surfaces of the fixed abutments. With this arrangement, however, the maximum volume of fluid which can be delivered in each direction of fluid flow is materially reduced in comparison with the maximum volume which could be delivered by a comparable non-reversible pump, as the latter equals the total of the maximum volumes which can be delivered in both directions of fluid flow by a reversible pump of this character.

When the direction of fluid flow is reversed the spaces 26!! and 2M exchange functions, becoming alternately inlet and outlet spaces. It is therefore desirable to modify simultaneously the arrangement of the vane slot ports so as at all times to supply to theinner ends of the vane slots of those vanes which are in contact with the abutments 236and 24 0, fluid under the same 75 pressure as that in whichever of the spaces 26!! or 26! are at the time serving as the outlet or high pressure spaces, in order to assist in keeping the ends of said vanes firmly in contact with the vane track surfaces of these abutments. An

arrangement by which this may be accomplished is shown, partly schematically, in Figs. 9 and 10.

The end plates 26 are accordingly modified to provide four vane slot ports 264, indicated by dotted lines in Figs. 9 and 10, separate from the I vane slot ports 266 and 261, the latter being of equal length and positioned to connect with the inner ends of the vane slots as the vanes therein pass through the spaces 26!! and 26! respectively. The vane slot ports 264 are positioned radially in line with the ar'cs 215 on the inner ends of the abutments 236 and 245 and have an angular length substantially equal to or slightly greater than the angular lengthof the arcs 245. The vane slot ports 264 are adapted to be connected with whichever of the spaces 26!! or 26! are at the time the outlet or high pressure spaces and hence are connected through suitable passages with a circular duct 263 which in turn is connected through pipe 265 with a'valve chamber 212 by which connection is made to one or the other of spaces 26!) and 26! through pipes 268 and 269. Communication between the duct 263 and spaces 26!] and 26! is controlled by a pair of check valves 2'!!! and 21!, one of which opens to admit fluid to pipe 263 whenever the pressure therein is less than the pressure in pipes 268 or 769, but which closes when pressure in the pipe 265=exceeds the pressure in those-pipes. Figs. 9 and 10 show the valve chamber 212 connected with the spaces 26! and 266,.respectively, each of which is an outlet or high pressure space when the vane track elements are in the positions of adjustment shown in the respective figures. By this arrangement the chamber 212 and the vane slot ports 26 are at all times supplied with fluid from whichever ofthe spaces 266 or 26! is atthe time the high pressure or outlet space.

The reversible pump herein disclosed possesses substantially all the advantages of the non-reversible type in addition to its ability to reverse the direction of fluid flow and to deliver full volume in both directions of flow. This reversing feature has numerous well known advantages and makes the'pump suitable for use in a larger number of applications and for a larger number-of purposes.

While the device has bee described as apump it will also operate asa fluid motor when sup plied with fluid under suitable pressure. The

cycle of operation will, of course, be reversed. When employed as a motor, it may be desired to introduce mechanical or hydraulic pressure means tending toforce the vanes outward to maintain themat all times in contact with the vane track, particularly operated at low rotative speeds.

It will be undertood that, if desired, my invention can be applied to a single-acting pump, thus,

' for example, a single pumping space may be employed, a single fixed abutment and a single movable abutment, provided the pump is of the nonreversible type; also that such a single-acting pump can be made reversible by employing two adjustable abutments.

It is to be understood that the several embodiments of my invention have been described for the purpose of illustrating the principle of operation and construction of the apparatus of my present invention, and that changes, some of if the motor is to bewhich have been indicated in the foregoing description, may be made without departing from the spirit and scope of the invention, which is defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a rotary pump or motor of variable capacity, a casing, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a stationary abutment carried by said casing and having a track surface of fixed curvature, means for varying the capacity of said pump or motor abutment having a track surface of fixed curvature, said last-mentioned abutment being movable to alter the capacity of said pump or motor and to vary the circumferential length of said track, and a flexible element carried at one end by said stationary abutment and having its opposite end engaging a portion of said movable abutment in all positions of said movable abutment.

2. In a rotary pump or motor of variable capacity, a rotary assembly including a rotor and a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a first abutment coacting with a portion of the peripheral surface of the rotary assembly, a second abutment coacting with the vanes of another portion of said rotary assembly and adjustable radially with respect thereto to vary the capacity of the pump or motor, a flexible projection secured tonne of said abutments and extending in a circumferential direction to the other of said abutments and forming a track element connecting said abutments to guide said vanes radially as they pass therebetween, and means carried by said other abutment for maintaining the track surface of the end of said flexible projection-even with the corresponding surface of said abutment as the adjustable abutment is adjusted radially to vary the capacity of the pump or motor.

3. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and therefor including a fixed abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, a movable abutment coacting with the ends of the vanes of another portion of said surface and adjustable radially with respect to said surface to vary the capacity of the pump or motor, a projection secured to said fixed abutment and extending in a circumferential direction therefrom to said movable abutment and forming a track element connecting said abutments to guide said vanes abutment the vanes pass smoothly between said,

abutments. 1

4. In a rotary pump or motor of variable capacity, a casing, a rotor, a plurality of 'vanes movable inwardly and outwardly of said rotor,

'an abutment carried by said casing and having a track surface of fixed curvature, means for varying the capacity of said pump or motor including a track for said vanes comprising a second abutment having a track surface of fixed curvature, said second abutment being movable outwardly of said rotor, a casing to alter the capacity of said pump or motor and 15 to vary the circumferential length of said track, and a flexible member secured at one end to said first abutment and having an extensible connection with said movable abutment, and means for controlling the flexing of said flexible member conformably to all positions of said movable element, whereby in all positions thereof the a flexible element carried at one end by said stationary abutment and having its opposite end engaging a portion of said movable abutment in all positions of said movable abutment, and means for exerting bending force upon said flexible element to alter its configuration conformably to the position of said movable abutment to cause said vanes to pass smoothly around said track without abrupt changes in radial velocity.

6. In a rotary pump or motor of variable 08-- pacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a track having a surface adapted to coast with the exposed ends of said vanes to control the reciprocation thereof, said track including an abutment which is adjustable radially to,vary the capacityof the pump or motor and a stationary abutment having a flexible projection secured thereto and extending to and connected with said adjustable abutment, said flexible projection having a predetermined curvature and being free from force tending to change its curvature when said adjustable abutment is in one position of adjustment, means carried by said adjustable abutment for exerting bending force upon said flexible projection in a direction tending to increase its curvature when said adjustable abutment is moved in one direction away from said force-free position, and means carried by said adjustable abutment for exerting bending forceupon said flexible projection in a direction tending to des crease the curvature of said abutment when said adjustable abutment is moved in the opposite direction away. from said force-free position.

7. .lIn a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, acasing therefor including a first abutment coasting with the ends of the vanes of a portion of the peripheral surface of the rotor, a second abutment coacting with the ends of the vanes of another por-= tion of said surface, one of said abutments beingadjustable radially with respect to the surface of the rotor to vary the capacity of the pump or,

motor, a member extending in a circumferential direction and forming a vane track element connecting said abutments to guide the vanes radialiy as they pass therebetween, said member being secured at one end to one of said abutments, and at its opposite end having an extensible connection with the other of said abutments, said member having a flexible portion, and means in part supported on the abutment having said extensible connection for control ling the flexing of said member conformably to the adiusted ment;

8, In a rotary pump or motor of variable ca pacity, a' rotor, a plurality of vanes movable inwardly andv outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, a projection on one of said abutments and extending in a circumferential direction to the other abutment and forming a'track element connecting said abutments to guide said vanes radially as they pass therebetween, said projection having a flexible portion, means for radially adjusting one of said abutments with respect to the surface of the rotor to vary the capacity of the pump or motor, and means carried by the end ofsaid projection and by the other of said abutments for maintaining the track surface of the end 01 said projection substantially even with the corresponding surface of said other abutment and for controlling the flexing of said projection when the adjustable abutment is moved to change the capacity of thepump or motor, thereby providing the right curvature to produce a smooth guiding of the vanes at all capacities.

9. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including side walls coasting with the position of said adjustable abutsides of the rotor, a first abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, asecond abutmentcoacting with the ends of-the vanes of another portion of said surface, one of said abutments being adjustable radially with respect to the SUI-,3

face of the rotor to vary the capacity of the pumpor motor, a member extending in a circumfiguration of said flexible portion when the ad-' justable abutment is moved to change the capacity of the pump or motor, thereby providing the right curvature in said memberto produce a smooth guiding or the vanes at all capacities.

10. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly-and outwardly of said rotor, a casing therefor including side walls coacting with the sides of the rotor, a first abutment coasting with the ends of thevanes of a portion of the peripheral surface of the rotor, a second abutment coactingwith the ends of the vanes (vi-another portion of said surface, one of said abutments being adjustable radially witth respect to the surface of therotor to vary the capa'cityof thepump or motor, 'a member extending in a circumferential direction forming a van'e track-element connecting said, abutments, to guide the "vanes radially as they pass therebetween, said member being secured at one end' to orient said abutments, and at its opposite end having a rigid portion, said member having a flexible portion, and means carried by the" other of 'said "abutments for maintaining thetrack surfaces of 4 said rigid p ortion andbf'said other abutmentis portion when the adjustable abutment is moved the pump or motor, curvature in said to change the capacity of thereby providing the right member to produce a smooth guiding of the,

vanes at all capacities.

11. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwarcfly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the peripheral. surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, one of said abutments being adjustable radially with respect to the surcircumferential direction face of the rotor to vary the capacity of the pump or motor, a member extendinglin a circumferential direction and forming a vane track element connecting said abutments to guide the vanes radially as they pass therebetween, said member being secured at one end to one of said abutments, and at its opposite end having a rigid portion having a track surface, said member having a flexible portion, the other of said abutments having a rigid arm having a track surface and means on said arm coacting with said rigid portion to maintain said track surfaces even and for altering and controlling the configuration of said flexible portion when the adjustable abutment is moved to change the capacity of the pump or motor, thereby providing the right cur vature in said member to produce a smooth'guiding of the vanes at all capacities.

12. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the periph eral surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, one of said abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motorgand a member extending in a forming a' vane track element connecting said abutments to guide the vanes radially as they pass therebetween, said member being secured at one end to one of said abutments, and at its opposite end having a rigid portion having a track surface said member having a flexible portion, the other of said abutments being provided with a pair of spaced rigid arms having track surfaces, said rigid portion being disposed between said arms, a pair of keys arms in alignment and to alter and control the flexible portion conformto which said adjustable configuration of said ably to the position element is adjusted.

J3. In a rotary pump or motor of variable.

capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, one of said abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motor, a member extending in a circumferential direction forming a vane track element connecting said abutments to guide the vanes raeral surface of the rotor, a

carried by the casing for rocking said rigid por- 'tion to alter and control the configuration. of said flexible portion conformably to the adjusted position of said adjustable abutment.

14.1n a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the periphsecond abutment coacting with the ends of the vanes of another portion of said surface, one of said-abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motor, a member extending in a circumferential direction forming a vane track element connecting said abutments to guide the vanes radially as they pass, therebetween, said member'being secured at one end to one of said abutments, and at its opposite end having a rigid portion having a track surface; a lever projecting fromsaid rigid portion, said member having a flexible portion, means carried by the other of said abutments for maintaining alignment between the track surface of said rigid portion and of said abutment and forming a pivot for said lever, and means on said casing for causing said lever to rock about said pivot and alter and control the configuration of said flexible portion conformably to the adjusted position of said adjustable abutment.

15. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing cumferential direction forming a vane track element connecting said abutments to guide the vanes radially as they pass therebetween,- said member being secured at one end to one of said abutments, and at its opposite end having a rigid portion provided with a track surface, said member having a flexible portion, means on the other of said rigid portion to maintain alignment between the track surface thereof and the track surface of said abutment and forming a pivot about which said rigid portion may rock, said casing having a slot therein, and a lever flxed to said rigid portion the outer portion of which is adapted to coact with said slot to cause the rocking of said rigid portionso as to alter and control the configuration of said flexible portion ccnformably to the adjusted position of said adjustable abutment.

16. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including side walls coacting with the sides of the rotor, a track for said vanes includabutments coacting with said to the other and to the rotor to alter the capacity of said pump or motor and to vary the circumferential length of said track, and means carried by said track elements and actuated simultaneously with said adjusting means for exerting force upon said flexible element to alter and control its shape.

17. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, each of said abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motor, a member extending in a circumferential direction forming a vane track element connecting said abutments to guide the vanes radially as they pass therebetween, said member being secured at one end to one of said abutments, and at its opposite end having a sliding connection with the other of said abutments, said member having a flexible portion, and means carried by the abutment having said slidable connection for altering and controlling the configuration of said member, and means for radially adjusting either of said abutments while maintaining the other in close proximity to the surface of the rotor to vary the capacityof the pump or motor.

18. In a rotary pump or motor of-variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of aportion of the peripheral surface of the rotor, a second abutment coacting with the ends of the vanes of another portion of said surface, both of said abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motor, .a member extending in a circumferential direction forming a vane track element connecting said abutments to guide the vanes radially as they pass therebetween, said member being secured at one end to one of said abutments, and at its opposite end having a sliding connection with the other of said abutments, said member having a flexible portion, means carried by the abutment having said slidable connections for altering and controlling the configuration of said member, and means forsimultaneously adjusting both of said abutments relative to the surface of the rotor, one abutment being moved outwardly while the other is moved inwardly to vary the capacity, of the pump or motor.

19. In a pump or motor of variable capacity, a rotor having a plurality of vanes movable inwardly and outwardly thereof and a vane track of variable circumferential length surrounding said rotor and said vanes, said vane track including a pair of circumferentially spaced rigid track elements movable with respect to each other whereby the radial distance of the track surface of either of said spaced track elements from the rotor may be made less than, equal to or greater than the radial distance of the track ing an adjustable abutment coacting with the ends of the vanes of one portion of the surface of said rotor, and. a fixed abutment coacting with the ends of the vanes of another portion of the surface of said rotor, said casing having a radial aperture provided with an inner shoulder, said fixed abutment comprising a rod-like member adapted to be received in said aperture and having an enlargement at its inner end having a vane track surface thereon andadapted to be held against said inner shoulder, a vane track member having a central portion and flexible end portions, said central portion having an aperture therein and adapted to be received upon said rod-like member and held against said shoulder by said enlarged endportion of the rod-like member.

21. In a rotary pump or motor of variable capacity, a rotor, a plurality of vanes movable inwardly and outwardly of said rotor, a casing therefor including a first abutment coacting with the ends of the vanes of a portion of the peripheral surface of the rotor, a second abutment coacting'with the ends of the vanes of another portion of said surface, one of said abutments being adjustable radially with respect to the surface of the rotor to vary the capacity of the pump or motor, a member extending .in a circumferential direction and forming a vane track element connecting said abutments to guide the vanes radially as they pass therebetween, said member being secured at one end to one of said abutments, said member having a flexible portion, and means carried by the opposite end of said member and by the said other abutment contiguous to said end for maintaining the track surface of said end substantially even with the corresponding surface of said contiguous abutment and for flexing said member when the adjustable abutment is moved to change the capacity of the pump or motor, thereby providing the right curvature to produce a smooth guiding of the vanes at all capacities.

HUGO A. CENTERVALL.

CERTIFICATE OF CORRECTION. Patent No. 2,1hl,171. December 27', 1938.

HUGO A CENTERVALL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1;, first column, line 15,, for the word "or" read of; line 60, for "These" read The; page 5 second column, line 22, for P'fhrough" read Thropghout page 7 first column, line 1 1;, for "function" read functioning; and second column, line 69-79, for "ooncenientiy' read convenient1yypa'ge 12, first column; line 55,, claim 18; for "connections" read connection; and that the said Letters Patent ahouldbegreed with this correction therein that the same may con- -'form to the record of the case in the Patent Office.

Signed and sealed this 1mm day of rebmr 12. 1939.

Henry Van Arsdale (Seal Acting cqnniaeioner of Patents. 

